Sheet-metal-working machine



H. A. AND R. H. GRIFFITHS.

SHEET METAL WORKING MACHINE.

APPLICATION HLED MAR 23, I921- Pa'tented June 28, 1921.

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SHEET METAL WORKING MACHINE.

APPLICATION FILED MAR.23, I92}- 1382,974 Patented June 28, 1921.

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SHEET METAL WORKING MACHINE. APPLICATION FILED MAR. 23. 1921..

Patented June 28, 1921.

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UNITED STATES HARRY ALBERT GRIFFITHS, OF

EDG-BAS'ION, BIRMINGHAM, AND RICHARD HANSON GRIFFITHS, OF SUTTON GOLDFIELD, ENGLAND.

SHEET-METAIi-WORKING MACHINE.

Specification of Letters Patent. Patented June 28, 1921.

Application filed March 23, 1921. Serial No. 454,832.

(GRANTED UNDER THE PROVISIONS THE ACT OF MARCH 3, 1921, 41 STAT. It, 1313.)

To all whom it may concern Be it known that we, HARRY ALBERT GRIF rrrHs, residing at 8 Chad road, Edgbaston, in the city of Birmingham, England, and RICHARD ANsoN GRIFFITHS, residing at Highfieldjl Sutton Coldfield, in the county of Warwick, England, subjects of the King of Great Britain and Ireland, have invented certain new and useful Improvements Relating to Sheet-Metal-Working Machines, for which we have filed application in England, August 26, 1919, of which the following is a specification.

This invention relates to sheet metal working machines, such as cutting, drawing, embossing and like presses, and has for its object to provide improved means for automatically feeding the sheet metal blanks to the tools.

The invention comprises the combination with a blank holder in which a stack of blanks are placed, of knife edge wedges or separating tools rotatable in a plane parallel with those of the blanks and adapted when rotated to enter between the bottom blank and those above it, together with means for lifting the separating tools so that the stack of blanks is raised clear of the bottom blank and the latter is left free to-fall down an inclined chute by gravity or be pushed out by any suitable mechanical device.

Referring to the six accompanying sheets of explanatory drawings Figure 1 is a plan, Fig. 2 an end view and Fig. 3 a cross section on 1-2, Fig. 1, of an automatic feeding device constructed in ac- 'cordance with this invention.

'Fig. 4 is a plan of a cam for lifting one of the separating tools and Fig. 5 is a plan of one of the separating tools.

Figs. 6, 7 and 8 are diagrammatic views illustrating stages in the operation of one of the separating tools used in the mechanism shown in Figs. 1-5.

Fig. 9 is a plan, and Fig. 10 an end view of a modified form of our automatic feed 'in mechanism.

ig. 11 is a cross section through the holding and separating elements in the plane of the line 3+4 Fig. 9. a

Figs. 12, 13 and 14 are diagrammatic views illustrating stages in the operation of the mechanism shown in Figs. 911.

The same reference lettersin the different views indicate the same or similar parts.

In carrying the invention into effect as shown in Figs. l-8 an annular blank holder a for containing circular blanks is mounted on a chute 6 which is arranged in an inclined position in front of the cutting or shaping tools of the machine. The lower or fixed tool is indicated by 0. Above the holder project a pair of pins 03 for supporting those blanks in the stack which are not contained within the ring a. At diametrically opposite sides of the holder are arranged a pair of eccentric rotatable knife edge wedges or separating tools 6 which when rotated can enter between the bottom blank and those above it sufficiently to separate the bottom blank and support the others. On each spindle f which carries the separating tool at its upper end, is arranged a collar 9 adapted by means of a lateral projection h to engage a stationary cam 2'. Each separating tool can also engage the holder through the medium of a piece j for the purpose of' lifting the holder. The holder is arranged to move vertically on guide stems 70 against the action of springs Z. After the separating tools have been rotated into engagementwith the stack of blanks, further rotation causes the said collar by its engagement with the cam, to lift the separating tools and at the same time to lift also the stack of blanks and the holder, leaving the bottom blank free. As the underside of the holder is .now clear of the chute o the bottom blank can slide down the chute by gravitytoward the tools. The operation of the mechanism is afterward reversed, the holder and blanks being lowered to the original position and the separating tools withdrawn from the blanks prior to a repetition of the sequence of operations. The two spindles f of the separating'tools areconnected for simultaneous operation by a link m acting on lovers 7?. at the lower ends of the spindles, and any convenient provision is made for actuating thespindles automatically from the crank shaft or other moving part "of the'press at the proper intervals during the operations of the tools.

'The holder is returned after the lifting movement by the' springs Z.

Referring to Figs. 68 the blanks as indicated by 1" he initially within the holder as shown in Fig. 6. Only a few blanks are shown. It'will be understood that the stack of superimposed blanks may contain any convenient number, new blanks being intermittently placed on the top of the stack while the lower ones are being removed by the mechanism. The distance of the opera tive edge of the separating tool a above the upper surface of the chute on which the blanks are supported isequal to the thicknessof a single blank. In Figs. 6-8 only one separating tool is shown; there is an other like tool at the .opposite side of the blank as shown in Figs. 1-3. During the first part of the rotation of thespindle f, the. separating tool enters between the bottom blank and the, remainder and comes into contact with the part j of the holder as shown in Fig. 7. Further rotation of'the spindle causes the cam like projection h of the collar 9 to engage the fixedcam e, and the interaction of the parts it and '5 causes the spindle to rise .The separating tool thereupon lifts the. upper blanks andthe holder as shown in Fig. 8, leaving the bottom blank free to slide under the holder by gravity to the feeding tools.

During the transit of the blanks from the holder to the tools, each is preferably held in turn :by an automatic stop 8- (Fig. 1) beneath an oiling pad which is brought into contact with the blanks by means actuated in conjunction with the tools. The oiling ad is not shown but its position is indicatedby dotted lines t. (Fig. 1). On withdrawingthesmp the blank completes its advance and is arrested by stops u at the proper position between the tools. After the shaping, cutting or other 'operation,' the blanks are ejected in any usual manner. In Fig. 1" a blank 1 is shown resting against the stops to in position over the fixedor bottom tool 0. The stop 8 is actuated at the proper .intervals automatically by a link o attached toa lever to on the shaft p. 7

Referring to the mechanism shown in Figs.

9 ,11, the blank holder is formed by'a pair of pins 01. secured to the base or chute b and 'avertically movable stema which is held down by a spring blade Z.- The pin a is guidedby a bridgepiece 00. Instead of two separating tools e acting simultaneously on opposite sides of the blanks, a single tool e is arranged .to produce the preliminary-separation of the blanksat one side only, and

vided Witha projection 71. which can coact with a fixed cam i. Rotation of the spindle on the spindle and also to a lever 0 on the shaft p. Likewise the spindle f of the tool 6 is provided with a projection h .coacting with a fixed cam i'. The tool e'is actuated by a link m connected to a lover of on the shaft p. Both tools are held downby. blade springs g g acting on the spindles f f' respectively. i The .tool 6 .is also adapted to lift the holder elementaythe latter being chainfered on its rear-side (Fig. 11) to permit .of the tool 6 sliding beneath it.

The action of the mechanism will readily be followed by reference to. Figs. 12 1i. Initially the tools occupy the relative positions shown in Figs. 9 and 12 from the lat ter of which the blanks havebeen omitted for clearance of illustration. The tool ;e.fi-rst comes into operation and separates the upper blanks 1" at one side from the lower blank as shown in Fig. 13,- sufficiently to permit the subsequent entry of -the tools, This now comes into action, and by passing between the blanks lifts the upper ones .from the bottom blank. ,It also :lifts theholder element a, and due to the interactionof the parts it and i the blanks r and the. holder element a, areprais'ed completely clear of the I is effected by a link m connected to a 'levera bottom blank as shownin Fig. 14. .During or discharged bottomblank may be arrested by a stop-sto ,permitof oiling operation by a lubricating pad t-as alreadydescribed. By means ofthis invention it is :only necessary for the attendant to maintain I the supply of blanks in the holder, the feeding forward of each bottom blank-in turn being effectedautomatically. v 1 Y V In some .cases any convenient provisioniis made for pushing the blanks forward by mechanical means instead of -"allow-ing them to slidedown the'chute by gravity :as above described. 7 a V To prevent derangementor. damage due to two blanks passing out of the holder simultaneonsly the blanks may be caused-to pass over a balance before reaching the-tools. Provision wouldth'en be ima de so that'two blanks would tilt the balance and cause the feeding forward of the blanks to be arrested.

Having thus described our invention what We claim as new and desire to secure by Letters Patent is 2-- 1. In mechanism for automatically feeding sheet metal blanks to the tools of cutting, drawing, embossing and like presses, the combination of a blank holder in which a stack of blanks is placed, rotatable knife edge separating tools adapted to enter between the bottom blank and those above-it, and means for lifting the separating tools so that the stack of blanks is raised clear of the bottom blank and the latter is thereby released for transfer to the press tools, substantially as described.

2. In mechanisms for automatically feeding sheet metal blanks to the tools of cutting, drawing, embossing and like presses, the combination of a movable blank holder in which a stack of blanks is placed, rotatable knife edge separating tools adapted to enter between the bottom blank and those above it, and means for lifting the holder and the separating tools so that the stack of blanks is raised clear of the bottom blank and the latter is thereby released for transfer to the press tools, substantially as described.

3. In mechanisms for automatically feeding sheet metal blanks to the tools of cutting, drawing, embossing and like presses, the combination of a movable holder in which a stack of blanks is placed, rotatable knife edge separating tools adapted to enter between the bottom blank and: those above it, means for lifting the separating tools so that the stack of blanks is raised clear of the bottom blank, and an inclined chute down which the released bottom blank can slide to the press tools, substantially as described.

4:. In mechanisms for automatically feeding sheet metal blanks to the tools of cutting, drawing, embossing and like presses, the combination of a holder for a stack of blanks, a pair of rotatable knife edge separating tools one of which enters first between the bottom blank and those above it, the other then following into the aperture thus made and serving as a support for the stack, and means for raising the stack through the medium of one or both of the separating tools, clear of the bottom blank, leaving the latter free for transfer to the press tools, substantially as described.

In testimony whereof we have signed our names to this specification.

HARRY ALBERT GRIFFITHS. RICHARD HANSON GRIFFITHS. 

